Gas compressor



oct. 17, 1939. F J, FETTE 2,176,300

4 GAS COMPRESSOR J FRANK J. FETTE Oct. 17, l939. F `J FETTE l 2,176,300

' GAS COMPRESSOR Filed Dec. e, 1957 sheets-sheet 2 37 5 T l Mmm FRANK J. FETTE @as /1- v All r/M GMW ` ose 17, 1939 UNITED' STATES PATENT formes 2.11am Gas commission marmermpam. application December aus?, sel-nim. 11am schim (ci. sse-m) 10 allmoving parts, and for avoiding friction,in a

simple, inexpensive, and readily assembled v'group of elements having a single driving element actu#V ating a plurality of pistons of short stroke. Y `Other objects and advantages of the invention l5 will appear in connection with the description of a preferred embodimentwhich has been selected for purposes of illustration in the accompanying drawings. It will be evident-to those skilled in the art that many changes in sizefiorm, number of 20 parts and in the details of construction and arf .rangement of elements may be made witlioigit departure from the principles ofthe inventlonfor sacrifice of its advantages. l

In the drawings, Figure 1 is a central horizontal 8l section with the driving cam in elevation; Fig. 2 is an end elevation with parts in section; Fig. 3 isa side elevation with parts broken away and parts in section: 4 isla horizontal section on the line IV-IV .of Fig. 3; Fig. 5 is a fragmentary sectional I0 view of the intake valve on an enlarged scale,

taken on the line V-V lof Pig. 6; and Pig. 6 is a fragmentary end view in elevation .of the intake v ve.

A drive shaft AI to be driven by a high speed 8l motor, is mounted in vsuitable bearings 2 and 3 in end members l and l which are secured, as by screws C, to a central casing 1. y Y

The end member l has formed `therein a pair of cylinders I to receive the large ends l of pistons I l l. and the end member I has formed therein smaller cylinders I I to receive the small ends I2 of the pistons Il. These double pistons, reciprocating in the allnedy cylinders l and Iiglhave their central lportions adapted for sliding engagement within il guideways Il upon opposite sides of the casing section 1. These guideways have substantially parallel sides .for contact with a laterally projecting portion of each piston to prevent rotation' thereof, so that a pair of frusto-conical rollers Il I mounted within. each piston on pivots Il will-be held with the smaller end Iof-each roller directed 'toward lthe'drive shaft I, the vertex 'of the angle formed by the sidesof the rollers being at the axis y of' the shaft I. A cam 'Il is formed upon. or Il secured to, the shaft I with the periphery o f the vertex, the rollers will cam extending between .the rollers I4 of each piston and having its surfaces which engage the rollers beveled to conform to the taper of the y rollers.

Preferably. the surfaces of the cam will be genv I erated by the use of milling cutters and grinding cones of the shape of the rollers I4, held in contact with the cam and reciprocated longitudinally of the shaft in simple harmonic motion with one complete reciprocation of the cutters or cones durl0 ing onerefvolution of the cam. I' When formed in this manner, the cam, at every point during its i rotation, will be of uniform section in every longitudinal axial plane, so that the rollers will bear upon opposite sides in line contacts radially from vthe shaft without binding, and since the taper of the rollers and of the cam surface at any line of mutual contact corresponds to the taper of bevel gears or to the taper of two cones having the same run upon the cam without friction due to unequal speeds.

' The rollers I l will preferably be provided with.

. thrust bearings Ii` to resist radial pressure and the needle rollers Il will be interposed between the rollers I4 and theirpivots I5. The sides of the 25 pistons within the casing section 'I bear against the walls of the casing at each side of the guide- .ways I3 directly opposite the cam, and in thismanner, the portion of the piston within the cylinder is relieved of side thrust against the cylinder 80 y wall.V

The cylindrical portion` of the central casing section 1 surrounding the shaft I will be lled with a lubricant which will be in contact with the cam II, the rollers Il, the guideways I 3, and all of the surfaces of the'pistons which enter the lubricant chamber. vEscape ofthe lubricant from the 'casing along the shalt I will be prevented by a suitable gland Il which may be of the type shown in which rubber washers 2l surrounding the shaft 40 are compressed by springsv 2| against the shaft and against bronze bearing washers .22.v Y

On the outer end of the member l opposite each cylinder tis secured a manifold 2l provided with an intake valve and an exhaust valve 25. Similar manifolds 2l are secured on the outer end of 'the member Ifoppoaite the vcylinders II, these manifolds each beinglprovided with an intake valve 21 and an exhaust or outlet valve 2l. The valves ,21, '25, 21, and Il', may be of any suitable 50 type, butasshown, they are identical in construc- -V tion and reversible.

Referring to Pigs. 5 and 6. each valve has an element 2l provided with a plurality of ports 3l which arenormally held closed by a closure ring 65 3| having guide pins 32 slidable in bushings33 y members 29 and 34 together and a spring 31 interthe other side 4l through the pipe 42.

posed between the outer wall of the manifold and the connected members 29 and 34 holds one vor the other of these members against its seat at the end of the vcylinder which it serves. The ring 3| moves inward toward the cylinder in the intake valves and outward away from the cylinder in thel outlet valves. l

A water jacket 38 is formed on one side of the central casing section 1. Water enters this jacket at one side 39 through the pipe 40 and leaves on One end wall 43 of the jacket has secured thereto a manifold 44 and the other end -wall 45 has a manifold 46. Connecting these manifolds are curved tubes 41 having their ends secured within the 'wallsv43 and 45. Each manifold 23 is connected to the manifold a4 by a pipe 4a and each manifold 4s is connected to a manifold 26 by a pipe 48.

Gas entering a manifold 23 through an intake pipe 50 is drawn into a cylinder 8 as the piston end 9 on its intake stroke recedes from the valve 24,

and when, upon the return stroke, the pressure of the compressed gas in thev cylinder becomes greater than the pressure of the gas in the manifolds and in the tubes 41, 48, and 49, the valve 25 will open to allow the compressed gas to leave the cylinder 8 through the valve 25 into the outlet side of the manifold 23, whence it proceeds through the pipe 48, manifold 44, tubes 41, manifold 46, pipe 49, manifold 26, and intake valve 2l into the cylinder H which lies in line with the cylinder 8 in which the gas is being compressed.

As the piston ill pauses at the end of the compression stroke in cylinder 8 and begins its return or intake stroke for that cylinder, the pressures in the assembly just enumerated will become uniform and the valves 25 and2`l will be closed by the action of their springs 35. As the intake stroke continues, gas from the intake pipe Eil will be drawn into the cylinder 8 as before, while simultaneously the gas in the opposed and smaller cylinder il, already under partial compression, is further compressed until it is forced out through the valve 2t into the outlet side of the manifold 26 from which the outlet pipe 5l leads to a storagel tank, a heat-*transfer apparatus, or to other devices, depending on the uses to which the compressed'gas is to be put.

The tubes 41 are curved to provide for such ex- Dansion or contraction asmay occur because of heating by the gas or cooling by the water in the jacket, a change in the curvature compensating for greater or less length caused by the tempera-'- ture changes without undue strain on their connections with the walls of the jacket.

While only two cylinders are illustrated .in each end member, it'will of course, be vobvious in view of the presentnart, that as many may be provided .as can be economically driven by the motor to be used to give the volumedesired.

The method of assembly will also be evident, since the end member 41s detachable froml the arrasoo casing section 1I permitting the withdrawal of the pistons. cam. and drive shaft, after the flange 52 has been removed from the shaft l. The drawings are to be considered as purely illustrative many details being omitted, such as water jackets for-the cylinders, well known in the art, and manifolds or other connections between the intake and outlet pipes, such modications theskill of those familiar with this surfaces engaging between said rollers and arranged to cause reciprocating movement of said piston, the angle and position of the contacting surfaces being such as to cause the relative speeds Aofbgth to be equal at all points of contact.

2"; A compression pump comprising a central casing section, end members secured upon opposite ends of the casing and each provided with a plurality of cylinders and with a central bearing for a drive shaft, a piston for each cylinder having one end in a cylinder in one end member and the other end in a cylinder in the other end member, a portion of the piston intermediate oi its ends being slidably and non-rotatably mountedV in the central casing section, a drive shaft journalled inthe bearings in the end members, a cam upon the drive shaft, spaced tapering rollers mounted within each piston and engaging opposite surfaces of the cam, the slope of the rollers and of the surfaces of the cam at every line of contact being that of two cones having the samevertex in the airis of rotation of the drive shaft.

3. In apump, a piston mounted forrreciproca- 4. In a pumpvtwo cylindersin alinement with each other, a piston mounted for reciprocation within said cylinders, a guideway for the piston between the cylinders, a cam mounted on a shaftwhose axis is substantially parallel .with the path of reciprocation of the piston, the cam engaging within the piston to produce reciprocation thereof, spaced tapering rollers mounted within the piston for engagement with the opposite surfaces of the cam, the slope of the rollerskand ofthe surfaces oi the cam being such. as to cause the relative speeds of both to be equal at' every point in their line of contact. l

5. A structure as in claim. 4 having a chamber for lubricant surrounding'the cam, the rollers, and thecentral portion of the piston.

' FRANK J. FETTE. 

